Six-phase staggered synchronous rectification BUCK converter

Abstract

The invention discloses a multi-phase interleaving parallel synchronous rectification BUCK converter, an integral power supply module is a 6-phase interleaving synchronous rectification BUCK converter, a power supply power part main body adopts a three-level topology, and each module of a step-down adjustment unit forms two groups of 180-degree interleaving parallel BUCK converters. Three groups of 120-degree interleaved parallel BUCK converters are also formed among the three modules of the whole power supply module; the whole power supply module forms a 6-phase interlaced BUCK converter by calculating the interlacing of each module per time, the switching frequency is improved by 6 times in phase change, the current ripple is reduced due to the valley filling effect, the output stability is correspondingly improved, the problems of the output current stability and ripple of the high-power power supply are solved, and finally the 10-6 magnitude index is broken through.

Description

Technical Field

[0001] The invention relates to a switching power supply, in particular to a six-phase interleaved synchronous rectification BUCK converter. Background Art

[0002] At present, switching power supplies have been widely used in industrial automation control, communication equipment, LED lighting, medical equipment and other fields. With the development of the electronics industry, the development direction of switching power supplies is miniaturization, light weight, high efficiency and high performance. In order to improve the performance of switching power supplies, many new topologies and control methods have emerged.

[0003] Electronic devices have increasingly higher requirements for power supply performance, especially in high-power and high-current output situations, where switching power supply efficiency and output ripple indicators are critical. Multi-phase interleaved synchronous rectification BUCK converters can significantly improve switching power supply efficiency and reduce output ripple.

[0004] In the prior art, in order to improve the efficiency of the switching power supply and reduce the output ripple when the traditional BUCK circuit outputs high power and high current, two groups of BUCK circuits are generally used to form a 180-degree staggered parallel synchronous BUCK converter. As electronic equipment has higher and higher requirements for the output ripple of the switching power supply, the traditional BUCK circuit can no longer meet the power supply requirements.

[0005] In view of this, the present invention is proposed. Summary of the invention

[0006] The purpose of the present invention is to provide a six-phase interleaved synchronous rectification BUCK converter to solve the above technical problems existing in the prior art.

[0007] The objective of the present invention is achieved through the following technical solutions:

[0008] The six-phase interleaved synchronous rectification BUCK converter of the present invention has a main circuit topology structure including six-phase interleaved synchronous rectification BUCK converters, and multiple units are connected in parallel;

[0009] The entire topology consists of six BUCK circuits, divided into three groups, with six current loops connected in parallel and one voltage loop. Take the first group as an example:

[0010] Each group includes two MOSFETs Q1 and Q2 in an interleaved synchronous rectification BUCK topology, two inductors L1 and L2, two current transformers TA1 and TA2, two diodes D1 and D2, and at least one output filter capacitor C1 and resistor R7.

[0011] Compared with the prior art, the six-phase interleaved synchronous rectification BUCK converter provided by the present invention adopts a three-level topology for the main body of the power supply power part. Each module of the buck adjustment unit forms two groups of 180-degree interleaved parallel BUCK converters, and three groups of 120-degree interleaved parallel BUCK converters are formed between the three modules of the overall power module. In terms of calculation, each time the modules are interleaved, the entire power module forms a six-phase interleaved BUCK converter, which increases the switching frequency by 6 times in disguise. The current ripple is reduced due to the valley filling effect, and the output stability is correspondingly improved, which solves the output current stability and ripple problems of high-power power supplies, and finally breaks through 10 -6 Magnitude indicator. BRIEF DESCRIPTION OF THE DRAWINGS

[0012] Figure 1 A schematic diagram of the main topology principle of a six-phase interleaved synchronous rectification BUCK converter provided in an embodiment of the present invention;

[0013] Figure 2 The software control flow chart of the embodiment of the present invention. DETAILED DESCRIPTION

[0014] The following is a clear and complete description of the technical solutions in the embodiments of the present invention in conjunction with the drawings in the embodiments of the present invention; it is obvious that the described embodiments are only part of the embodiments of the present invention, not all of the embodiments, which does not constitute a limitation of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the protection scope of the present invention.

[0015] First, the terms that may be used in this article are explained as follows:

[0016] The term “and / or” means that either or both of them can be realized at the same time. For example, X and / or Y means both “X” or “Y” and “X and Y”.

[0017] The terms "include", "comprises", "contains", "has" or other descriptions with similar semantics should be interpreted as non-exclusive inclusion. For example, including certain technical feature elements (such as raw materials, components, ingredients, carriers, dosage forms, materials, dimensions, parts, components, mechanisms, devices, steps, procedures, methods, reaction conditions, processing conditions, parameters, algorithms, signals, data, products or products, etc.) should be interpreted as including not only certain technical feature elements explicitly listed, but also other technical feature elements known in the art that are not explicitly listed.

[0018] The term "consisting of..." means excluding any technical feature elements not explicitly listed. If this term is used in a claim, it will make the claim closed, so that it does not contain technical feature elements other than the technical feature elements explicitly listed, except for the conventional impurities related to them. If this term only appears in a clause of a claim, it only limits the elements explicitly listed in the clause, and the elements recorded in other clauses are not excluded from the overall claim.

[0019] Unless otherwise specified or limited, the terms "installed", "connected", "connected", "fixed" and the like should be understood in a broad sense, for example: it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or it can be an indirect connection through an intermediate medium, or it can be the internal communication of two components. For ordinary technicians in this field, the specific meanings of the above terms in this article can be understood according to specific circumstances.

[0020] The orientation or position relationship indicated by terms such as "center", "longitudinal", "lateral", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", "clockwise", "counterclockwise", etc. are based on the orientation or position relationship shown in the drawings and are only for the convenience and simplification of description, and do not explicitly or implicitly indicate that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as a limitation of this document.

[0021] The contents not described in detail in the examples of the present invention belong to the prior art known to professionals in the field. If no specific conditions are specified in the examples of the present invention, the conditions are carried out according to the conventional conditions in the field or the conditions recommended by the manufacturer. If the manufacturer is not specified in the reagents or instruments used in the examples of the present invention, they are all conventional products that can be purchased commercially.

[0022] The six-phase interleaved synchronous rectification BUCK converter of the present invention has a main circuit topology structure including six-phase interleaved synchronous rectification BUCK converters, and multiple units are connected in parallel;

[0023] The entire topology consists of six BUCK circuits, divided into three groups, with six current loops connected in parallel and one voltage loop. Take the first group as an example:

[0024] Each group includes two MOSFETs Q1 and Q2 in an interleaved synchronous rectification BUCK topology, two inductors L1 and L2, two current transformers TA1 and TA2, two diodes D1 and D2, and at least one output filter capacitor C1 and resistor R7;

[0025] The front-stage power supply of the three BUCK circuits uses one AC-DC module respectively, for a total of three AC-DC modules. The AC input sides of the three AC-DC modules are connected in the order of A / B, B / C, and C / A, with a phase shift of 120°.

[0026] Each set of BUCK circuits is phase shifted by 180°.

[0027] The first BUCK circuit consists of two MOSFETs Q1 and Q2 and two diodes D1 and D2 to form a bridge structure, which is connected to two inductors L1 and L2, and then connected to an output filter capacitor C1, and then connected to a resistor R7.

[0028] The two MOSFETs (Q1, Q2) are connected to driving signal units (DRI and DR2), respectively.

[0029] The working modes of the first group are divided into four modes:

[0030] Mode 1: DR1 outputs pulse, Q1 is turned on, and the working process is U in —Q1—L1—load, inductor L1 stores energy and the current increases, the voltage of resistor R7 and capacitor C1 increases, providing energy for the load; because the current on inductor L2 has not been released in the previous process, the current cannot change suddenly, and at this time it passes through diode D2 for freewheeling;

[0031] Mode 2: DR1 and DR2 have no pulses at this time, Q1 and Q2 are turned off, and the working process is U in —D1 / D2—L1 / L2—load; because the current on inductors L1 and L2 has not been completely released in the previous process, the current cannot change suddenly. At this time, the two inductors continue to flow through diodes D1 and D2.

[0032] Mode 3: DR2 outputs pulse, Q2 is turned on, and the working process is U in -Q2-L2-load, inductor L2 stores energy and the current increases, the voltage of resistor R7 and capacitor C1 increases, providing energy for the load; because the current on inductor L1 has not been fully released in the previous process, the current cannot change suddenly, and at this time it needs to pass through diode D1 for freewheeling.

[0033] Mode 4: DR1 and DR2 have no pulses at this time, Q1 and Q2 are turned off, and the working process is U in —D1 / D2—L1 / L2—load; because the current on inductors L1 and L2 has not been completely released in the previous process, the current cannot change suddenly. At this time, the two inductors continue to flow through diodes D1 and D2.

[0034] The load includes a resistor R7 and a capacitor C1.

[0035] The specific work of the three topology groups involves the DSP distributing the frequency reference signal of the entire chassis to each DC power supply module, delaying and interleaving according to the address.

[0036] In summary, the six-phase interleaved synchronous rectification BUCK converter of the embodiment of the present invention has a power supply part composed of three BUCK power modules, each module is composed of two groups of synchronous BUCK converters interleaved at 180 degrees in parallel, and three groups of 120 degrees interleaved are formed between the three modules, thereby forming a six-phase interleaved synchronous rectification BUCK converter, which achieves higher efficiency and smaller output ripple.

[0037] The main circuit topology structure in the embodiment of the present invention is mainly aimed at the output current stability problem of the high-power switching power supply. The overall power module has 6-phase staggered synchronous rectification BUCK converters. The main body of the power part adopts a three-level topology. Each module of the buck adjustment unit itself forms two groups of 180-degree staggered parallel BUCK converters. The three modules of the overall power module also form three groups of 120-degree staggered parallel BUCK converters. In terms of calculation, each module is staggered, and the entire power module forms a 6-phase staggered BUCK converter, which increases the switching frequency by 6 times in disguise. The current ripple is reduced due to the valley filling effect, and the output stability is correspondingly improved, which solves the output current stability and ripple problems of the high-power power supply, and finally breaks through 10 -6 Magnitude indicator.

[0038] In order to more clearly demonstrate the technical solution and technical effects provided by the present invention, the embodiments of the present invention are described in detail with specific embodiments below.

[0039] Example 1

[0040] A schematic diagram of a six-phase interleaved synchronous rectification BUCK converter is shown in the figure. Figure 1 As shown, Q1 and Q2 represent MOS tubes of the first group of staggered parallel synchronous rectification BUCK topology, D1 and D2 represent diodes in the synchronous rectification BUCK topology, L1 and L2 represent inductors, TA1 and TA2 represent current transformers, and C1 represents an output filter capacitor; similarly, Q3 and Q4 represent MOS tubes of the second group of staggered parallel synchronous rectification BUCK topology, D3 and D4 represent diodes in the synchronous rectification BUCK topology, L3 and L4 represent inductors, TA3 and TA4 represent current transformers, and C2 represents an output filter capacitor; Q5 and Q6 represent MOS tubes of the third group of staggered parallel synchronous rectification BUCK topology, D5 and D6 represent diodes in the synchronous rectification BUCK topology, L5 and L6 represent inductors, TA5 and TA6 represent current transformers, and C3 represents an output filter capacitor.

[0041] The front-stage power supply of the three groups of BUCK circuits of the six-phase interleaved synchronous rectification BUCK converter uses three AC-DC modules respectively. The AC input side of the front-stage module is connected in the order of A / B, B / C, and C / A, which can not only avoid the imbalance of three-phase power, but also the independent connection of A / B, B / C, and C / A can effectively reduce the power frequency ripple on the output side. The three groups of BUCK circuits are controlled by a digital PWM controller, and the phase shift is 120° to achieve the interleaving between the three groups of BUCK circuits. Each group of BUCK circuits is controlled by a digital PWM controller, and the phase shift is 180° to achieve the interleaving of a single group of BUCK circuits. The entire topology consists of six BUCK circuits, which are connected in parallel through six current loops, and a voltage loop is added to achieve constant voltage output.

[0042] The three groups of BUCK circuits have the same working mechanism except that the phases are different. The first group of BUCK is taken as an example for introduction. The BUCK circuit consists of Q1, Q2, D1, and D2 to form a bridge structure. The current waveforms in the two inductors are staggered. Two current transformers take the inductor current to form two current loops to achieve closed-loop control. The multiplied switching ripple is superimposed on the output capacitor. Its working mode is divided into four modes.

[0043] Mode 1: DR1 outputs pulse, Q1 is turned on, and the working process is U in —Q1—L1—load (resistor R7 and capacitor C1), inductor L1 stores energy and the current increases, and the voltage of resistor R7 and capacitor C1 increases, providing energy for the load; because the current on inductor L2 has not been released in the previous process, the current cannot change suddenly, and at this time it passes through diode D2 for freewheeling.

[0044] Mode 2: DR1 and DR2 have no pulses at this time, Q1 and Q2 are turned off, and the working process is U in —D1 / D2—L1 / L2—load (resistor R7 and capacitor C1); because the current on inductors L1 and L2 has not been completely released in the previous process, the current cannot change suddenly. At this time, the two inductors continue to flow through diodes D1 and D2.

[0045] Mode 3: DR2 outputs pulse, Q2 is turned on, and the working process is U in -Q2-L2-load (resistor R7 and capacitor C1), inductor L2 stores energy and the current increases, and the voltage of resistor R7 and capacitor C1 increases, providing energy for the load; because the current on inductor L1 has not been fully released in the previous process, the current cannot change suddenly, and at this time it needs to pass through diode D1 for freewheeling.

[0046] Mode 4: DR1 and DR2 have no pulses at this time, Q1 and Q2 are turned off, and the working process is U in—D1 / D2—L1 / L2—load (resistor R7 and capacitor C1); because the current on inductors L1 and L2 has not been completely released in the previous process, the current cannot change suddenly. At this time, the two inductors continue to flow through diodes D1 and D2.

[0047] The specific work of the three topologies involves the DSP distributing the frequency reference signal of the entire chassis to each DC power module, and delaying and interleaving according to the address. The software control flow chart is as follows Figure 2 shown.

[0048] The above is only a preferred specific embodiment of the present invention, but the protection scope of the present invention is not limited thereto. Any changes or substitutions that can be easily thought of by any technician familiar with the technical field within the technical scope disclosed in the present invention should be included in the protection scope of the present invention. Therefore, the protection scope of the present invention should be based on the protection scope of the claims. The information disclosed in the background technology section of this article is only intended to deepen the understanding of the overall background technology of the present invention, and should not be regarded as an admission or in any form that the information constitutes prior art known to those skilled in the art.

Claims

1. A six-phase interleaved synchronous rectification BUCK converter, characterized in that: The main circuit topology includes six-phase interleaved synchronous rectifier BUCK converters, and multiple units are connected in parallel; The entire topology consists of six BUCK circuits, divided into three groups, with six current loops connected in parallel and one voltage loop. Take the first group as an example: Each group includes two MOSFETs (Q1, Q2), two inductors (L1, L2), two current transformers (TA1, TA2), two diodes (D1, D2) and at least one output filter capacitor (C1) and resistor (R7) in two interleaved synchronous rectification BUCK topologies.

2. The six-phase interleaved synchronous rectification BUCK converter according to claim 1, characterized in that: The front-stage power supply of the three BUCK circuits uses one AC-DC module respectively, for a total of three AC-DC modules. The AC input sides of the three AC-DC modules are connected in the order of A / B, B / C, and C / A, with a phase shift of 120°. Each set of BUCK circuits is phase shifted by 180°.

3. The six-phase interleaved synchronous rectification BUCK converter according to claim 2, characterized in that: The first BUCK circuit consists of two MOSFETs (Q1, Q2) and two diodes (D1, D2) forming a bridge structure, which is connected to two inductors (L1, L2), then connected to an output filter capacitor (C1), and then connected to a resistor (R7).

4. The six-phase interleaved synchronous rectification BUCK converter according to claim 3, characterized in that: The two MOSFETs (Q1, Q2) are respectively connected to two driving signal units (DRI and DR2).

5. The six-phase interleaved synchronous rectification BUCK converter according to claim 4, characterized in that: The working modes of the first group are divided into four modes: Mode 1: The drive signal unit 1 (DRI) outputs a pulse, MOSFET 1 (Q1) is turned on, and the working process is U in —Q1—L1—load, inductor 1 (L1) stores energy and the current increases, the voltage of resistor (R7) and output filter capacitor (C1) increases, providing energy for the load; because the current on inductor 2 (L2) has not been released in the previous process, the current cannot change suddenly, and at this time it passes through diode 2 (D2) for freewheeling; Mode 2: The two drive signal units (DRI and DR2) have no pulses at this time, and the two MOSFETs (Q1, Q2) are turned off. The working process is U in —D1 / D2—L1 / L2—load; because the current on the two inductors (L1, L2) has not been completely released in the previous process, the current cannot change suddenly. At this time, the two inductors (L1, L2) continue to flow through the two diodes (D1, D2); Mode 3: The drive signal unit 2 (DR2) outputs a pulse, MOSFET 2 (Q2) is turned on, and the working process is U in -Q2-L2-load, inductor 2 (L2) stores energy and the current increases, the voltage of resistor (R7) and output filter capacitor (C1) increases, providing energy for the load; because the current on inductor 1 (L1) has not been fully released in the previous process, the current cannot change suddenly, and at this time it needs to pass through diode 1 (D1) for freewheeling; Mode 4: The two drive signal units (DRI and DR2) have no pulses at this time, and the two MOSFETs (Q1, Q2) are turned off. The working process is U in —D1 / D2—L1 / L2—load; because the current on the two inductors (L1, L2) has not been completely released in the previous process, the current cannot change suddenly. At this time, the two inductors (L1, L2) continue to flow through the two diodes (D1, D2); The load includes a resistor (R7) and an output filter capacitor (C1).

6. The six-phase interleaved synchronous rectification BUCK converter according to any one of claims 1 to 5, characterized in that: The specific work of the three-group BUCK circuit topology involves the DSP distributing the frequency reference signal of the entire chassis to each DC power supply module, delaying and interleaving according to the address.

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